I tried to get this achievement once, long time ago, I had some people who were willing to help but then we had the same poblem. Searching for 5 minutes...I don't see how it could take so long to find each others' lobby especially knowing that no one plays this mod. It should take not more than 10-15 seconds. We gave up and I never tried it since then. Add me if you want to, we can try together.